In recent years, in accordance with a progress in establishment of an optical subscriber network, an FTTH (Fiber To The Home), an installation of an optical fiber cable directly into a subscriber's home, is remarkably becoming pervasive in relation to an Internet access.
When installing an optical fiber cable into a subscriber's home, it is convenient to use an optical-connector-equipped optical fiber cable, in which an optical connector is coupled to an end part of the optical fiber cable in advance, in order to facilitate a connection to an adaptor of an indoor optical equipment.
FIGS. 12 and 13 show an example of such an optical-connector-equipped optical fiber cable.
The optical-connector-equipped optical fiber cable 1 is configured such that an optical connector 5 is coupled to an end of an optical fiber cable 3.
The optical connector 5 is what is called an SC connector and, as shown in FIG. 13, includes a ferrule 7 which holds an end part of an optical fiber, a plug frame 9 which covers a circumference of the ferrule 7, a stop ring 13 which is fitted and coupled to a rear end of the plug frame 9 to provide, behind the ferrule 7, a space 11 for connection and accommodation of the optical fiber cable 3, a boot 15 which is fitted onto a rear end of the stop ring 13 to protect the optical fiber cable 3 drawn out of the stop ring 13, and a grip 19 which is disposed on an outer side of the plug frame 9 to serve as a gripping portion when engaging with or disengaging from (attaching to or detaching from) an adaptor 17 of an optical equipment.
The optical fiber cable 3 extending from the space 11 along the boot 15 is fixed and positioned by means of a fastening ring 21 which is tightly fastened onto the rear end of the stop ring 13 and an auxiliary ring 22 which engages with a rear end of the fastening ring 21.
The ferrule 7 accommodated in the plug frame 9 is positionally regulated toward the front by contacting a diameter-enlarged portion 7a thereof to a step (a diameter-reduced portion) 9a on an inner periphery of the plug frame 9. The ferrule 7 is pressed against the step 9a by a compression coil spring 24 which is fitted between the diameter-enlarged portion 7a and the stop ring 13. Due to the elastic support by the compression coil spring 24, the ferrule 7 is rearwardly displaced in accordance with a butting force against an abutting object when connecting the optical connector 5 to the adaptor 17, whereby a stable pressing force required for the connection is obtained.
The optical connector 5 is usually provided with a cap 26 which is fitted, at the time of storage, on an end portion to protect the ferrule 7.
A method shown in FIGS. 14 and 15 has hitherto been proposed as an introducing method for inserting the optical-connector-equipped optical fiber cable 1 described above through an electrical wiring conduit in a subscriber's home.
In this method, a holder 27 having a towing portion 27a, to which a wire or the like for towing is hooked, and configured to be able to attach to and detached from the grip 19 of the optical connector 5 is provided, and the holder 27 is attached to an end of the optical connector 5 when inserting through an electrical wiring conduit 28 in a subscriber's home and is detached after the insertion (see, e.g., Patent Document 1).    Patent Document 1: Japanese Published Patent Application: JP 2003-322727A